1. Field
Example embodiments relate to a substrate surface treatment method, a method of fabricating image sensor by using the treatment method, and an image sensor fabricated by the same. Other example embodiments relate to a substrate surface treatment method to improve low illuminance characteristics of an image sensor by removing defects on the surface of a substrate, a method of fabricating image sensor by using the treatment method, and an image sensor fabricated by the same.
2. Description of the Related Art
In general, an image sensor may be a semiconductor device that transforms photonic images into electrical signals. Such image sensors may be divided into two categories: CCDs (Charge Coupled Devices) and CMOS Image Sensors. A charge coupled device may be a device that includes MOS capacitors close to each other, and in such a device, electric charge carriers may be stored in the capacitors and may be transferred. A CMOS image sensor may be a device that includes a control circuit and a signal-processing circuit as a surrounding circuit implemented in CMOS technology. In such a device, the same amount of transistors as pixels may be formed, and the outputs may be sequentially extracted using a switching mechanism.
A CMOS image sensor may be divided into two regions: an APS (Active Pixel Sensor) array region that generates electrical signals by detecting light and a logic region (surrounding logic region) that processes electrical signals generated by the APS array region. The APS array region may include a photoelectric transformation unit that transforms incident lights into electrical signals. The greater the area of the photoelectric transformation unit, e.g., a photo diode, the better the photosensitivity characteristic of the image sensor. Although the integration density of a CMOS image sensor may be increased, increasing the size of the active pixel sensor array region has shown limitations.